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Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions

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El enlace cruzado reversible de las coronas de poliisopreno en micelas, comicelas de bloque y arquitecturas de

Paul A Rupar¹, Graeme Cambridge, Mitchell A Winnik

¹School of Chemistry, University of Bristol, Bristol, United Kingdom, BS8 1TS.

Journal of the American Chemical Society

|October 5, 2011

Resumen

El enlace cruzado catalizado por platino de poliisopreno (PI) en micelas de copolímero de bloque ofrece una estabilización estructural reversible y un contraste de imagen mejorado. Este nuevo método permite la creación de nanoestructuras complejas y huecas mediante la eliminación selectiva de componentes centrales.

Área de la Ciencia:

Química de Polímeros La Química de Polímeros es la química de los polímeros.
Ciencia de los materiales Ciencia de los materiales.
Nanotecnología La nanotecnología es la nanotecnología.

Sus antecedentes:

En estudios anteriores se utilizó la hidrosilación para el enlace cruzado irreversible de las coronas de poliisopreno (PI) en micelas de copolímero de bloque de poli (ferrocenildimetilesilano) (PFS).
Se sabe que el catalizador de Karstedt facilita las reacciones de hidrosilación en presencia de silanos.

Objetivo del estudio:

Para investigar el potencial del catalizador de Karstedt solo para inducir el enlace cruzado en PI coronas.
Para explorar la reversibilidad de este mecanismo de enlace cruzado y sus aplicaciones en la fabricación de nanoestructuras y la obtención de imágenes.

Principales métodos:

Tratamiento de micelas cilíndricas de copolímero de bloque PI-b-PFS con el catalizador de Karstedt en ausencia de silanes externos.
Investigación de la reversibilidad del enlace cruzado utilizando 2-bis ((difenilfosfino) etano (dppe) como agente quelante del platino.
Aplicación del método de enlace cruzado para mejorar el contraste de la microscopía electrónica de transmisión (TEM) y crear nanoestructuras jerárquicas.

Principales resultados:

El catalizador de Karstedt por sí solo induce el enlace cruzado de coordinación Pt(0)-olefina de las coronas de PI, distinto de la hidrosilación.
El enlace cruzado inducido por Pt(0) mejora significativamente la estabilidad de las estructuras micelares PI-b-PFS.
El enlace cruzado es reversible con la adición de dppe, que secuestra el platino.
Este proceso permite la mejora selectiva del contraste de TEM entre los dominios PI y poli (dimetilsiloxano) (PDMS).
Una comicella jerárquica en forma de bufanda se deconstruyó con éxito, dejando una estructura hueca después de la eliminación selectiva del núcleo PFS-b-PDMS.

Conclusiones:

La coordinación Pt(0)-olefina representa una estrategia de enlace cruzado novedosa y reversible para el poliisopreno.
Este método proporciona una poderosa herramienta para estabilizar las nanoestructuras autoensambladas y crear materiales avanzados.
La capacidad de ajustar el enlace cruzado y el desenlace cruzado abre nuevas vías para el diseño y la manipulación de nanoestructuras complejas.

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